API - application program interface

Related Terms

API, an abbreviation of application program interface, is a set of routines, protocols, and tools for building software applications. The API specifies how software components should interact and APIs are used when programming graphical user interface (GUI) components. A good API makes it easier to develop a program by providing all the building blocks. A programmer then puts the blocks together.

Types of APIs

There are many different types of APIs for operating systems, applications or for websites. Windows, for example, has many API sets that are used by system hardware and applications — when you copy and paste text from one application to another, it is the API that allows that to work.

Most operating environments, such as MS-Windows, provide an API so that programmers can write applications consistent with the operating environment. Today, APIs are also specified by websites. For example, Amazon or eBay APIs allow developers to use the existing retail infrastructure to create specialized web stores. Third-party software developers also use Web APIs to create software solutions for end-users.

Popular API Examples

Programmable Web, a site that tracks more than 13,000 APIs, lists Google Maps, Twitter, YouTube, Flickr and Amazon Product Advertising as some of the the most popular APIs. The following list contains several examples of popular APIs:

1. Google Maps API: Google Maps APIs lets developers embed Google Maps on webpages using a JavaScript or Flash interface. The Google Maps API is designed to work on mobile devices and desktop browsers.